He has a girlfried

Well if he didn't tell you maybe he's nervous, or maybe he likes you and his girlfriend and doesn't know what to do, or he's a player. Any way time never stops love so if he likes you enough to drop his gf then yay! =)

Hmmm well so he likes and he has a girlfriend ...He might just be a really sweet guy stop flirting with him so much and ask him about his girlfriend but not right away.

Uh-oh. So he's been hitting on you, not telling you about his gf, and not breaking up with her? It may be that he's a sweet guy, but I'm not buying it yet. Sounds to me like he might be looking for something on the side. If I were you, I'd cool down the flirting until he gets his other affairs in order. If he breaks up with his girlfriend and then comes calling to you, a relationship may be possible. But don't get played.

I've always been a true believer in not breaking up happy home, but if he's not happy maybe something can actually come out of all these flirtatious signs. Ask him but not directly, start talking about random things and bring it up.